Oscillation-generator



LA DE FOREST.-

OSCILLATION GENERAIOR. APPLICATIIION FILED MAY I3. 1915.

1 ,3 1 4,252 Patented Aug. 26, 1919.

javerzidz 6642/ 4% 5 41/3 19 /WMQW UNITED, STATES PATENT OFFICE.

LEE DE FOREST, OF NEW YORK, N. Y., ASSIGNOR TO DE FOREST RADIO TELEPHONE AND TELEGRAPH COMPANY, OF NEW YORK, Y., A CORPORATION OF DELAWARE.

oscrnLArion-cnnnna'ron.

' To all whom it may concern:

Be it known that I, Lnnnn Foster, a citizen of the United States, residing at New York city, county of Bronx, State of New York, have made a certain'new and useful Invention in ,Oscillation-Generators, of which the followin is a specificat on.

This invention re ates to generators of oscillating, alternatin or pulsating currents.

The object of the invention is to provide a generator of oscillating, alternating or pul sating electric currents which is simple and eflicient. A further object is to provide an oscillation generator of the character referred to capable of generating oscillating, alternating or pulsating electric currents of substantially uniform amplitude.

Other objects of the invention will appear more fully hereinafter.

The invention consists substantially 'in the construction, combination, location and relative arrangement of parts all as will be more fully hereinafter set forth, as shown in the accompanying drawing and finally pointed out in the appended claims.

Referrin to the drawing The sing e figure is a view showing an arrangement of oscillating generator embodying my invention as applied for use in connection with radio systems.

In carrying out In invention I employ a closed, and preferab evacuated vessel or bulb in which are located cold and hot electrodes, and I provide suitable circuit connections and current supply source to said sound waves.

electrodes, and where the generator is employed in connection with radio systems I associate the generator with a suitable radiating system having means connected thereto or associated therewith for altering or moditying theradiations. from the system either manually, as through a telegraph key, or

otherwise, as for instance, a telephone trans mitter in accordance'with signal code or -Referring to the drawing I have shown the evacuated vessel or bul U having two cold plate orwi electrodes W, in electrical connection wit each other and two cold grid electrodes G in electrlcal connection with eachother. The two cold plate. or wing electrodes having a circuit connection to one side or terminal of the hot electrode F, which circuit connection includes an in.-.

Specification of Letters Patent. Patented Aug. 26, 1919.

Application filed May 13, 1915. Serial No. 27,771.

ductance coil 1 and a source of current supply mdicated at B, the ositive side of which is connected to the col plate or wing electrodes W and the negative side to one termicluded in said circuit is an inductance coil P,

which constitutes, in the form shown, a couling member in association with a coil S, in the antenna earth system N E the couling being preferably a loose coupling. here the apparatus is to be used for telephoning purposes the antenna has associated therewith or includes therein a microphone transmitter M. Where the apparatus is to be used for telegraphic communication a Morse telegraph key K is bridged across a portion of the inductance S. If desired, the grid and plate circuit may be inductively associated with the plate and filament circuit through inductance L as shown.

It is obvious that the current supply to the hot electrode F, or to the circuit connecbe controlled in any suitable or convenient manner, as, for instance, by the adjustable resistance R; Y

By reason of the arrangements above described and by impressing an electromotive force within the space between the cold plate or wing electrode W and the hot electrode from the current source B, the deviceU, with its electrodes and their associated circuits and circuit connections as described becomes a generator of oscillating, alternating or pulsating electric currents which are impressed upon the circuit which connects the grid and plate electrodes, the frequency of which depends upon the condition of the :spatial relation of the electrode member contamed therein, the value of the electrol tion of cold plate or wing electrodes W, may

oscillating, alternating or pulsating currents in said circuit connection are impressed upon said antenna earth system, and with a natural period of oscillation in said circuit, the same as that in said oscillating circuit. The emission of wave trains from' the antenna earth system may be controlled in accordance with the telegraphic code through the telegraph key K which acts to short circuit a portion of the inductance S: Or,

if desired, the amplitude of the oscillations,

induced in the antenna earth system may be varied by and in accordance with sound waves falling upon the microphone transmitter M in the usual manner. It is obvious that the wave length of the emitted wave trains may be altered in amanner well understood in the art.

I am unable at the present time to give a wholly satisfactoryexplanationof the theory of the generator action of the apparatus. I have discovered, however, as hereinabove stated that a system constructed as shown and described and energized from a suitable current source becomes the seat of continuous oscillations and it is my opinion that the phenomenon depends, upon the inductive effect of successively applied charges or surges of potential upon the grid and plate elec-,

trodes which charges or surges have the power to afiect momentarily the conducti ity of the surrounding 'or inter-connectmg medium within the vessel in such manner that the action, when set up," is self perpetuating.

It is obvious that the principles of my invention may be embodied in various arrangements and circuit connections without departure from the spirit and scope of my invention as defined in theclainn, but having now set forth the objects and n.' ture of my invention and circuit arrangemens embodying the principles thereof, what-I claim as new and useful and of my own invention, and desire to secure by Letters P3.tt nt, is,-

1. In a system for generating oscillations,

a work circuit and means forgenerating and I transmitting the generated oscillations to said work circuit includingadevice having a hot and two cold electrodes, an oscillatory circuit connecting the cold electrodes, and a second circuit connecting one of said cold electrodes and said hot electrode and inductively associated with said oscillatory circuit.

"2. In a system for generating oscillations, a work circuit and means for generating and transmitting the generated oscillations to said work circuit includin a dev'ice having a hot and two cold electro es, an oscillatory circuit connecting the cold electrodes, a

second circuit connecting one of said cold electrodes and said hot electrode and in rdiictiyely associated with said oscillatory cira cuit, and a source of current included in said second circuit.

In a system forgenerating oscillations,,-

a work circuit and means for generating and I transmitting the generated, oscillations to said work circuit including an evacuatedvessel containing filament, gridand plate el ec-. trodes, an oscillatory circuit connectin the grid and plate electrodes, and a se'con cir.-

cuit connecting the plate and filament electrodes and inductively associated with said oscillatory circuit.

4., In a system for generating oscillations,

a work circuit and meansfor generating and transmitting the generated oscillations to said work circuit including an evacuated vessel containing filament, grid and plate electrodes, an oscillatory circuit connecting the;

grid and plate electrodes,and a second circuit connecting the plate and filamentfelec;

W. A. DARBY, I M. AZ. GRAEVi.

of current 

